What cheaper amp for 2 500w RMS subs?

I'm getting 2 Type Rs, but I don't know which amp setup to go with. Should I get 2 seperate amps to power each sub, or should I go with one amp to power both? Any suggestions on what brand and model would be very helpful. I was looking at a Hifonics amp on Ebay that looked pretty nice. Cost efficiency is very important.. I would really like to spend under 300 on the amp, but if that means a huge sacrifice in performance the budget may increase.